In commercial building construction such as manufacturing plants, power plants and the like, there typically are numerous places where structures such as exhaust ducts, pipes, exhaust stacks, silos, conveyors, etc. penetrate the external wall or roof of the building, internal walls separating two sections of the same building or a common wall of two buildings. It is desirable to close off the openings surrounding these penetrating structures where they pass through the walls and roofs in order to complete the building envelope and prevent entry into the building of drafts, precipitation, dirt, etc. Furthermore, where noise levels within the building are high such as in power plants, it is desirable, if not a requirement, that the noise levels be reduced within the building envelope so that the noise levels outside of the building meet various codes, regulations and laws. This is especially true where the building is located near a residential area and the noise levels within the building reach a level equivalent to that of a jet engine such as in a power plant.
Many of the structures which penetrate the walls and roofs of these commercial buildings, such as the gas turbine exhaust ducts which are found in power plants, experience multi-directional expansion and contraction, vibration and high operating temperatures of 300 degrees F. or greater. Thus, in addition to sealing the openings between the penetrating structures and the walls and roofs of the buildings and attenuating the noise levels transmitted through the building envelope, it is desirable to isolate the expansion and contraction, vibration and heat of the penetrating structures from the building walls and roofs.
The openings between the penetrating structures and the walls or roofs can take many different configurations. For example, the penetrating structures can be round or rectangular in cross section and the holes in the building walls or roof can be round, square, rectangular or some other configuration required to accommodate a particular situation. Accordingly, if the closure system is to be most effective, the closure system must be readily adaptable to the different opening configurations providing for the complete closure of the openings even where the cross sectional configuration of the penetrating structure and the configuration of the hole in the wall or roof are different.
While typical closure systems used in the trade, such as sheet metal closure systems stuffed with fiber glass, are fairly effective in closing off the openings around penetrating structures, such closure systems have major deficiencies. Such systems are difficult to detail off sight and be assured that the detailed design is properly followed and the system properly installed in the field. With the use of sheet metal, such systems lack the insulating properties that are needed to deaden sound and vibration and to retard the transfer of heat through the closure system. These, prior art systems also lack the flexibility required over a wide range of temperatures to accommodate and isolate the vibrations and expansions and contractions of the penetrating structure from the walls and roof of the building and are a maintenance problem due to the need to periodically caulk such systems for the purpose of keeping such systems weathertight.